With continuous advancement, integrated circuit technology is widely applied to MEMS (Micro Electromechanical System), power devices, circuit systems and the like. A micro device, a micro system, a power device or the like is manufactured on a substrate made of semiconductor materials, by combining micro mechanical technology or other technologies with the integrated circuit manufacturing process.
Traditionally, the device is manufactured on a monocrystalline silicon substrate and a Silicon On Insulator (SOI) substrate.
For SOI substrate is expensive, and the process for manufacturing the micro mechanical device and the circuit is more complex than the process by the traditional process, which may significantly increase the cost of a product. For monocrystalline silicon substrate, a device is formed mainly by depositing a polycrystalline material and other insulating materials on the monocrystalline silicon substrate and then etching the deposited material. However, due to limitations of polycrystalline material deposition process and the material itself, the deposition thickness of the material is limited, which affects the performance of the device.
Particularly, the problem of the above method for manufacturing a device on the above monocrystalline silicon substrate is that, the polycrystalline material deposited on the substrate has a large stress which affects the realizable deposition thickness of the polycrystalline silicon and the performance of the device, especially for those devices showing high sensitive to stress. For example, a MEMS inertial sensor or a capacitive pressure sensor is operated by a principle that a polycrystalline silicon structure changes in capacitance under inertia or pressure. Thus, when such sensors are manufactured, the stress of the polycrystalline silicon may severely affect the performance of the device.